Sound box for talking machines



on. 2s 192.4.v 1,513,188

C. SCRAEIC SOUND BOX FOR TALKING MACHINES Filed Nov. 15, 1923 gli: ucnfot far? ,62' rabia @M l a um Patented Oct. 28, 1924.

PATENT OFFICE.

CARL SCRABIC, OF URBANA, OHIO.

SOUND BOX FOR TALKING MACHINES.

Application filed November 15, 1923. Serial No. 674,829.

To all whom t may concern.'

Be it known that I, CARL Sommo, a citizen ofthe United States, residing at Urbana, in the county of Champaign and State of Ohio, have invented certain new and useful Improvements in Sound Boxes for Talking Machines, of which the following is a speciication.

The present invention is directed to improvements in sound boxes for talking machines and has for its primary obj ect to provide an improved mounting for the diaphragm within the sound creating chamber of the sound box, the construction being such that the diaphragm will be held under such tension as to properly respond to the vibratory movement of the stylus arm.

With these and other objects in view, as will appear as the description proceeds, the

invention consists in the novel features of construction, combinations of elements and arrangements of parts, andl hereinafter Vto be fully described and pointed out in the appended claims.

In the accompanying drawing:

Figure l is a vertical sectional View through the device,

Figure 2 is a rear view of the sound box, with parts broken away to more clearly il lustrate Vthe invention, and

Figure 3 is a perspective view of one of the blocks.

Referring to the drawing l designates the sound box casing which includes an annular rim and liange 2 and 3, respectively,

the same being angularly disposed, as clearly shown in C.Figure l, to produce a diaphragm chamber. To the inner tace of the flange are secured arcuate plates 4:, preferably three in number, said plates having their ends spaced from each other and are provided with extensions 5, which are also disposed in spaced relation.

Located in the spaces between the plates t are elongated blocks 6 which are provided with inwardly directed centrally arranged projections 7 which occupy the spaces between the extensions 5 and are adapted to engage the periphery of the diaphragm 8 at spaced points to hold the same securely in place, and at the same time will permit the diaphragm to vibrate freely. These blocks are preferably formed from fiber or any other non-resonant material.

referably the peripheral edge of the diaphragm is confined between rubber or other non-resonant gaskets 9, which will insulate said diaphragm from adjacent metallic parts.

The blocks are freely slidable in a radial direction and are resiliently urged inwardly by theleaf springs 10, which are bowed inwardly and have their ends bearing against the inner periphery of the rim 2 and their bowed portions bearing against the central portions of the blocks. -These blocks being urged inwardly will cause the projections 7 to yieldably engage the periphery of the diaphragm in such manner as to properly hold the same centered but in no way enhancing the free vibration thereof.

The blocks 6 are held against lateral movement in one direction by the flange 3 and in the other direction by the cover plate ll which may be bolted to the casing by the same bolts which serve to hold the blocks in place, said plate having connected thereto the usual tone arm l2.

Asusual the stylus arm 13 has one of its ends fixed to the center of the diaphragm 8o and its other end suitably connected with the needle carrying socket member 14, and since this member forms no part of the present invention a detail description thereot` is not thought necessary.

While I have described the plates 4 as being bolted to the casing it may be preferable that the same be cast integral with the casing.

What is claimed is:r s

l. In a sound box, a casing including a chamber, a diaphragm mounted for vibration within said chamber, and spaced means projecting inwardly from the casing for engagement with the peripheral edge of said 95 diaphragm.

2. In a sound box, a casing including a chamber, a diaphragm mounted for vibra tion within said chamber, and spaced resiliently urged means projecting inwardly 100 from the casing for engagement with the peripheral edge of said diaphragm.

3. In a sound box, a casing including a chamber, a diaphragm mounted for vibration Within said Chamber, a plurality of blooks slidably mounted in the casing, problooks slidably and resiliently mounted in jeotions carried by the blocks, and means for 10 Jthe casing for yieldalole engagement with i'esiliently urging the blocks inWa-fdly to the periphery of the diaphragm at spaced cause the projections to yieldably engage 5 points.l the periphery of the diaphragm. Y. l

4. In a soundV box, a easing including u In'testim'ony whereof I iix. my signature. Chamber, adiaphragm mounted for Vibration Within said chamber` a plurality of i Y CARL SCRABIC. 

